<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Make Controller Kit - Firmware API: spi.c Source File</title>
<link href="mt_doxygen.css" rel="stylesheet" type="text/css" />
<link href="../resources/mt_doxytabs.css" rel="stylesheet" type="text/css" />
<style type="text/css">
<!--
.header {
	font-family: Verdana, Arial, Helvetica, sans-serif;
	font-size: 12pt;
	color: #222222;
}
-->
</style>
</head>

<body>
<table width="800" border="0">
    <tr>
      <td colspan="3">
        <form method="get" action="http://www.google.com/search">
          <div align="right">
            <input type="text"   name="q" size="25"
              maxlength="255" value="" />
            <input type="submit" value="Search" />
            <input type="hidden" name="sitesearch" value="makingthings.com/ref/firmware/html" />
          </div>
        </form>
       </td>
    </tr>
    <tr>
      <td><div align="center"><a href="http://www.makingthings.com">
				<img src="../resources/logo_brown_medium.png" alt="MakingThings"
									width="200" height="78" border="0" align="middle" longdesc="http://www.makingthings.com" /></a></div></td>
				<td><div align="center" class="header">
      		Make Controller Kit <br />
          Firmware API
      </div></td>
      <td><div align="center"><a href="http://www.makezine.com">
					<img src="../resources/make_logo.png" alt="MAKE Zine" 
										width="164" height="73" border="0" align="middle" longdesc="http://www.makezine.com" /></a></div></td>
    </tr>
</table>
</body>
</html>
<!-- Generated by Doxygen 1.5.4 -->
<script type="text/javascript">
<!--
function changeDisplayState (e){
  var num=this.id.replace(/[^[0-9]/g,'');
  var button=this.firstChild;
  var sectionDiv=document.getElementById('dynsection'+num);
  if (sectionDiv.style.display=='none'||sectionDiv.style.display==''){
    sectionDiv.style.display='block';
    button.src='open.gif';
  }else{
    sectionDiv.style.display='none';
    button.src='closed.gif';
  }
}
function initDynSections(){
  var divs=document.getElementsByTagName('div');
  var sectionCounter=1;
  for(var i=0;i<divs.length-1;i++){
    if(divs[i].className=='dynheader'&&divs[i+1].className=='dynsection'){
      var header=divs[i];
      var section=divs[i+1];
      var button=header.firstChild;
      if (button!='IMG'){
        divs[i].insertBefore(document.createTextNode(' '),divs[i].firstChild);
        button=document.createElement('img');
        divs[i].insertBefore(button,divs[i].firstChild);
      }
      header.style.cursor='pointer';
      header.onclick=changeDisplayState;
      header.id='dynheader'+sectionCounter;
      button.src='closed.gif';
      section.id='dynsection'+sectionCounter;
      section.style.display='none';
      section.style.marginLeft='14px';
      sectionCounter++;
    }
  }
}
window.onload = initDynSections;
-->
</script>
<div class="tabs">
  <ul>
    <li><a href="index.html"><span>Main&nbsp;Page</span></a></li>
    <li><a href="modules.html"><span>Modules</span></a></li>
    <li><a href="classes.html"><span>Data&nbsp;Structures</span></a></li>
    <li class="current"><a href="files.html"><span>Files</span></a></li>
    <li><a href="pages.html"><span>Related&nbsp;Pages</span></a></li>
  </ul>
</div>
<h1>spi.c</h1><a href="spi_8c.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/*********************************************************************************</span>
<a name="l00002"></a>00002 <span class="comment"></span>
<a name="l00003"></a>00003 <span class="comment"> Copyright 2006 MakingThings</span>
<a name="l00004"></a>00004 <span class="comment"></span>
<a name="l00005"></a>00005 <span class="comment"> Licensed under the Apache License, </span>
<a name="l00006"></a>00006 <span class="comment"> Version 2.0 (the "License"); you may not use this file except in compliance </span>
<a name="l00007"></a>00007 <span class="comment"> with the License. You may obtain a copy of the License at</span>
<a name="l00008"></a>00008 <span class="comment"></span>
<a name="l00009"></a>00009 <span class="comment"> http://www.apache.org/licenses/LICENSE-2.0 </span>
<a name="l00010"></a>00010 <span class="comment"> </span>
<a name="l00011"></a>00011 <span class="comment"> Unless required by applicable law or agreed to in writing, software distributed</span>
<a name="l00012"></a>00012 <span class="comment"> under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR</span>
<a name="l00013"></a>00013 <span class="comment"> CONDITIONS OF ANY KIND, either express or implied. See the License for</span>
<a name="l00014"></a>00014 <span class="comment"> the specific language governing permissions and limitations under the License.</span>
<a name="l00015"></a>00015 <span class="comment"></span>
<a name="l00016"></a>00016 <span class="comment">*********************************************************************************/</span>
<a name="l00017"></a>00017 <span class="comment"></span>
<a name="l00018"></a>00018 <span class="comment">/** \file spi.c </span>
<a name="l00019"></a>00019 <span class="comment">  SPI - Serial Peripheral Interface Controller.</span>
<a name="l00020"></a>00020 <span class="comment">  Methods for communicating with devices via the SPI protocol.</span>
<a name="l00021"></a>00021 <span class="comment">  //ToDo: need to do so locking around the Start code to make it thread safe</span>
<a name="l00022"></a>00022 <span class="comment">  //ToDo: make the naming scheme consistent for the SetActive() business</span>
<a name="l00023"></a>00023 <span class="comment">*/</span>
<a name="l00024"></a>00024 
<a name="l00025"></a>00025 <span class="comment">/* Library includes. */</span>
<a name="l00026"></a>00026 <span class="preprocessor">#include &lt;string.h&gt;</span>
<a name="l00027"></a>00027 <span class="preprocessor">#include &lt;stdio.h&gt;</span>
<a name="l00028"></a>00028 
<a name="l00029"></a>00029 <span class="comment">/* Scheduler includes. */</span>
<a name="l00030"></a>00030 <span class="preprocessor">#include "FreeRTOS.h"</span>
<a name="l00031"></a>00031 <span class="preprocessor">#include "task.h"</span>
<a name="l00032"></a>00032 <span class="preprocessor">#include "semphr.h"</span>
<a name="l00033"></a>00033 
<a name="l00034"></a>00034 <span class="comment">/* Hardware specific headers. */</span>
<a name="l00035"></a>00035 <span class="preprocessor">#include "Board.h"</span>
<a name="l00036"></a>00036 <span class="preprocessor">#include "AT91SAM7X256.h"</span>
<a name="l00037"></a>00037 
<a name="l00038"></a>00038 <span class="preprocessor">#include "spi.h"</span>
<a name="l00039"></a>00039 <span class="preprocessor">#include "io.h"</span>
<a name="l00040"></a>00040 <span class="preprocessor">#include "config.h"</span>
<a name="l00041"></a>00041 
<a name="l00042"></a>00042 <span class="comment">// Define the SPI select lines </span>
<a name="l00043"></a>00043 <span class="comment">// and which peripheral they are on that line</span>
<a name="l00044"></a>00044 <span class="preprocessor">#if ( CONTROLLER_VERSION == 50 )</span>
<a name="l00045"></a>00045 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL0_IO           IO_PA12</span>
<a name="l00046"></a>00046 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL0_PERIPHERAL_A 1 </span>
<a name="l00047"></a>00047 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL1_IO           IO_PA13</span>
<a name="l00048"></a>00048 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL1_PERIPHERAL_A 1 </span>
<a name="l00049"></a>00049 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL2_IO           IO_PA08</span>
<a name="l00050"></a>00050 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL2_PERIPHERAL_A 0 </span>
<a name="l00051"></a>00051 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL3_IO           IO_PA09</span>
<a name="l00052"></a>00052 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL3_PERIPHERAL_A 0</span>
<a name="l00053"></a>00053 <span class="preprocessor"></span><span class="preprocessor">#endif</span>
<a name="l00054"></a>00054 <span class="preprocessor"></span><span class="preprocessor">#if ( CONTROLLER_VERSION == 90 )</span>
<a name="l00055"></a>00055 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL0_IO           IO_PA12</span>
<a name="l00056"></a>00056 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL0_PERIPHERAL_A 1 </span>
<a name="l00057"></a>00057 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL1_IO           IO_PA13</span>
<a name="l00058"></a>00058 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL1_PERIPHERAL_A 1 </span>
<a name="l00059"></a>00059 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL2_IO           IO_PB14</span>
<a name="l00060"></a>00060 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL2_PERIPHERAL_A 0 </span>
<a name="l00061"></a>00061 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL3_IO           IO_PB17</span>
<a name="l00062"></a>00062 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL3_PERIPHERAL_A 0</span>
<a name="l00063"></a>00063 <span class="preprocessor"></span><span class="preprocessor">#endif</span>
<a name="l00064"></a>00064 <span class="preprocessor"></span><span class="preprocessor">#if ( CONTROLLER_VERSION == 95 || CONTROLLER_VERSION == 100 )</span>
<a name="l00065"></a>00065 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL0_IO           IO_PA12</span>
<a name="l00066"></a>00066 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL0_PERIPHERAL_A 1 </span>
<a name="l00067"></a>00067 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL1_IO           IO_PA13</span>
<a name="l00068"></a>00068 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL1_PERIPHERAL_A 1 </span>
<a name="l00069"></a>00069 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL2_IO           IO_PA08</span>
<a name="l00070"></a>00070 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL2_PERIPHERAL_A 0 </span>
<a name="l00071"></a>00071 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL3_IO           IO_PA09</span>
<a name="l00072"></a>00072 <span class="preprocessor"></span><span class="preprocessor">  #define SPI_SEL3_PERIPHERAL_A 0</span>
<a name="l00073"></a>00073 <span class="preprocessor"></span><span class="preprocessor">#endif</span>
<a name="l00074"></a>00074 <span class="preprocessor"></span> 
<a name="l00075"></a>00075 <span class="keyword">struct </span>Spi_
<a name="l00076"></a>00076 {
<a name="l00077"></a>00077   <span class="keywordtype">int</span> users;
<a name="l00078"></a>00078   <span class="keywordtype">int</span> channels;
<a name="l00079"></a>00079   xSemaphoreHandle semaphore;
<a name="l00080"></a>00080 } Spi;
<a name="l00081"></a>00081 
<a name="l00082"></a>00082 <span class="keyword">static</span> <span class="keywordtype">int</span>  Spi_Init( <span class="keywordtype">void</span> );
<a name="l00083"></a>00083 <span class="keyword">static</span> <span class="keywordtype">void</span> Spi_Deinit( <span class="keywordtype">void</span> );
<a name="l00084"></a>00084 <span class="keyword">static</span> <span class="keywordtype">int</span>  Spi_GetChannelIo( <span class="keywordtype">int</span> channel );
<a name="l00085"></a>00085 <span class="keyword">static</span> <span class="keywordtype">int</span>  Spi_GetChannelPeripheralA( <span class="keywordtype">int</span> channel );
<a name="l00086"></a>00086 <span class="comment"></span>
<a name="l00087"></a>00087 <span class="comment">/** \defgroup Spi</span>
<a name="l00088"></a>00088 <span class="comment">   The SPI subsystem allows the MAKE Controller to communicate with peripheral devices via SPI.  </span>
<a name="l00089"></a>00089 <span class="comment">   See \ref Eeprom module for an example use.</span>
<a name="l00090"></a>00090 <span class="comment">  </span>
<a name="l00091"></a>00091 <span class="comment">   \ingroup Controller</span>
<a name="l00092"></a>00092 <span class="comment">* @{</span>
<a name="l00093"></a>00093 <span class="comment">*/</span>
<a name="l00094"></a>00094 <span class="comment"></span>
<a name="l00095"></a>00095 <span class="comment">/**</span>
<a name="l00096"></a>00096 <span class="comment">  Configure the SPI channel.</span>
<a name="l00097"></a>00097 <span class="comment">  This function locks the I/O lines associated with the SPI channel so they cannot be</span>
<a name="l00098"></a>00098 <span class="comment">  used by another device on the same lines.</span>
<a name="l00099"></a>00099 <span class="comment">  @param channel An integer specifying the SPI channel to configure.</span>
<a name="l00100"></a>00100 <span class="comment">  @param bits An integer specifying the number of bits to transfer (8-16).</span>
<a name="l00101"></a>00101 <span class="comment">  @param clockDivider An integer specifying the desired divider from the serial clock (0 - 255).</span>
<a name="l00102"></a>00102 <span class="comment">  @param delayBeforeSPCK An integer specifying the delay, in ms, before the clock starts (0 - 255).</span>
<a name="l00103"></a>00103 <span class="comment">  @param delayBetweenTransfers An integer specifying how long, in ms, to wait between transfers (0 - 255).</span>
<a name="l00104"></a>00104 <span class="comment">  @return 0 on success.</span>
<a name="l00105"></a>00105 <span class="comment">*/</span>
<a name="l00106"></a><a class="code" href="group___spi.html#gcb528088437ee9b05515984b1033f748">00106</a> <span class="keywordtype">int</span> <a class="code" href="group___spi.html#gcb528088437ee9b05515984b1033f748" title="Configure the SPI channel.">Spi_Configure</a>( <span class="keywordtype">int</span> channel, <span class="keywordtype">int</span> bits, <span class="keywordtype">int</span> clockDivider, <span class="keywordtype">int</span> delayBeforeSPCK, <span class="keywordtype">int</span> delayBetweenTransfers )
<a name="l00107"></a>00107 {
<a name="l00108"></a>00108   <span class="comment">// Make sure the channel is locked (by someone!)</span>
<a name="l00109"></a>00109   <span class="keywordtype">int</span> c = 1 &lt;&lt; channel;
<a name="l00110"></a>00110   <span class="keywordflow">if</span> ( !( c &amp; Spi.channels ) )
<a name="l00111"></a>00111     <span class="keywordflow">return</span> <a class="code" href="group___error.html#g9ef65cc96e45d38307f661b86c330548" title="Lock attempt was unsuccessful.">CONTROLLER_ERROR_NOT_LOCKED</a>;
<a name="l00112"></a>00112 
<a name="l00113"></a>00113   <span class="comment">// Check parameters</span>
<a name="l00114"></a>00114   <span class="keywordflow">if</span> ( bits &lt; 8 || bits &gt; 16 )
<a name="l00115"></a>00115     <span class="keywordflow">return</span> <a class="code" href="group___error.html#g7736777a3f60d07d1aa15dc68b563abc" title="Parameter is not valid.">CONTROLLER_ERROR_ILLEGAL_PARAMETER_VALUE</a>;
<a name="l00116"></a>00116 
<a name="l00117"></a>00117   <span class="keywordflow">if</span> ( clockDivider &lt; 0 || clockDivider &gt; 255 )
<a name="l00118"></a>00118     <span class="keywordflow">return</span> <a class="code" href="group___error.html#g7736777a3f60d07d1aa15dc68b563abc" title="Parameter is not valid.">CONTROLLER_ERROR_ILLEGAL_PARAMETER_VALUE</a>;
<a name="l00119"></a>00119 
<a name="l00120"></a>00120   <span class="keywordflow">if</span> ( delayBeforeSPCK &lt; 0 || delayBeforeSPCK &gt; 255 )
<a name="l00121"></a>00121     <span class="keywordflow">return</span> <a class="code" href="group___error.html#g7736777a3f60d07d1aa15dc68b563abc" title="Parameter is not valid.">CONTROLLER_ERROR_ILLEGAL_PARAMETER_VALUE</a>;
<a name="l00122"></a>00122 
<a name="l00123"></a>00123   <span class="keywordflow">if</span> ( delayBetweenTransfers &lt; 0 || delayBetweenTransfers &gt; 255 )
<a name="l00124"></a>00124     <span class="keywordflow">return</span> <a class="code" href="group___error.html#g7736777a3f60d07d1aa15dc68b563abc" title="Parameter is not valid.">CONTROLLER_ERROR_ILLEGAL_PARAMETER_VALUE</a>;
<a name="l00125"></a>00125 
<a name="l00126"></a>00126   <span class="comment">// Set the values</span>
<a name="l00127"></a>00127   AT91C_BASE_SPI0-&gt;SPI_CSR[ channel ] = 
<a name="l00128"></a>00128       AT91C_SPI_NCPHA | <span class="comment">// Clock Phase TRUE</span>
<a name="l00129"></a>00129       ( ( ( bits - 8 ) &lt;&lt; 4 ) &amp; AT91C_SPI_BITS ) | <span class="comment">// Transfer bits</span>
<a name="l00130"></a>00130       ( ( clockDivider &lt;&lt; 8 ) &amp; AT91C_SPI_SCBR ) | <span class="comment">// Serial Clock Baud Rate Divider (255 = slow)</span>
<a name="l00131"></a>00131       ( ( delayBeforeSPCK &lt;&lt; 16 ) &amp; AT91C_SPI_DLYBS ) | <span class="comment">// Delay before SPCK</span>
<a name="l00132"></a>00132       ( ( delayBetweenTransfers &lt;&lt; 24 ) &amp; AT91C_SPI_DLYBCT ); <span class="comment">// Delay between transfers</span>
<a name="l00133"></a>00133   
<a name="l00134"></a>00134   <span class="keywordflow">return</span> <a class="code" href="group___error.html#gaa42bc036fbba18487ae9a15cd1f2f94" title="All&amp;#39;s well here.">CONTROLLER_OK</a>;
<a name="l00135"></a>00135 }
<a name="l00136"></a>00136 <span class="comment"></span>
<a name="l00137"></a>00137 <span class="comment">/** </span>
<a name="l00138"></a>00138 <span class="comment">  Read/Write a block of data via SPI.</span>
<a name="l00139"></a>00139 <span class="comment">  @param channel An integer specifying the device to communicate with.</span>
<a name="l00140"></a>00140 <span class="comment">  @param buffer A pointer to the buffer to read to, or write from.</span>
<a name="l00141"></a>00141 <span class="comment">  @param count An integer specifying the length in bytes of the buffer to read/write.</span>
<a name="l00142"></a>00142 <span class="comment">  @return 0 on success.</span>
<a name="l00143"></a>00143 <span class="comment">*/</span>
<a name="l00144"></a><a class="code" href="group___spi.html#gcbeac2d91c1f365f6f96a022ae50f619">00144</a> <span class="keywordtype">int</span> <a class="code" href="group___spi.html#gcbeac2d91c1f365f6f96a022ae50f619" title="Read/Write a block of data via SPI.">Spi_ReadWriteBlock</a>( <span class="keywordtype">int</span> channel, <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span>* buffer, <span class="keywordtype">int</span> count )
<a name="l00145"></a>00145 {
<a name="l00146"></a>00146   <span class="keywordtype">int</span> r;
<a name="l00147"></a>00147 
<a name="l00148"></a>00148   <span class="keywordtype">int</span> address = ~( 1 &lt;&lt; channel );
<a name="l00149"></a>00149 
<a name="l00150"></a>00150   <span class="comment">// Make sure the unit is at rest before we re-begin</span>
<a name="l00151"></a>00151   <span class="keywordflow">if</span> ( !( AT91C_BASE_SPI0-&gt;SPI_SR &amp; AT91C_SPI_TXEMPTY ) )
<a name="l00152"></a>00152   {
<a name="l00153"></a>00153     <span class="keywordflow">while</span>( !( AT91C_BASE_SPI0-&gt;SPI_SR &amp; AT91C_SPI_TXEMPTY ) )
<a name="l00154"></a>00154       ;
<a name="l00155"></a>00155     <span class="keywordflow">while</span>( !( AT91C_BASE_SPI0-&gt;SPI_SR &amp; AT91C_SPI_RDRF ) )
<a name="l00156"></a>00156       r = AT91C_BASE_SPI0-&gt;SPI_SR;
<a name="l00157"></a>00157     r = AT91C_BASE_SPI0-&gt;SPI_RDR;
<a name="l00158"></a>00158   }
<a name="l00159"></a>00159 
<a name="l00160"></a>00160   <span class="keywordflow">if</span> ( AT91C_BASE_SPI0-&gt;SPI_SR &amp; AT91C_SPI_RDRF )
<a name="l00161"></a>00161     r = AT91C_BASE_SPI0-&gt;SPI_RDR;
<a name="l00162"></a>00162 
<a name="l00163"></a>00163   <span class="comment">// Make the CS line hang around</span>
<a name="l00164"></a>00164   AT91C_BASE_SPI0-&gt;SPI_CSR[ channel ] |= AT91C_SPI_CSAAT;
<a name="l00165"></a>00165 
<a name="l00166"></a>00166   <span class="keywordtype">int</span> writeIndex = 0;
<a name="l00167"></a>00167 
<a name="l00168"></a>00168   <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span>* writeP = buffer;
<a name="l00169"></a>00169   <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span>* readP = buffer;
<a name="l00170"></a>00170 
<a name="l00171"></a>00171   <span class="keywordflow">while</span> ( writeIndex &lt; count )
<a name="l00172"></a>00172   {
<a name="l00173"></a>00173     <span class="comment">// Do the read write</span>
<a name="l00174"></a>00174     writeIndex++;
<a name="l00175"></a>00175     AT91C_BASE_SPI0-&gt;SPI_TDR = ( *writeP++ &amp; 0xFF ) | 
<a name="l00176"></a>00176                                ( ( address &lt;&lt; 16 ) &amp;  AT91C_SPI_TPCS ) | 
<a name="l00177"></a>00177                                (<span class="keywordtype">int</span>)( ( writeIndex == count ) ? AT91C_SPI_LASTXFER : 0 );
<a name="l00178"></a>00178 
<a name="l00179"></a>00179     <span class="keywordflow">while</span> ( !( AT91C_BASE_SPI0-&gt;SPI_SR &amp; AT91C_SPI_RDRF ) )
<a name="l00180"></a>00180     ;
<a name="l00181"></a>00181 
<a name="l00182"></a>00182     *readP++ = (<span class="keywordtype">unsigned</span> char)( AT91C_BASE_SPI0-&gt;SPI_RDR &amp; 0xFF );
<a name="l00183"></a>00183   }
<a name="l00184"></a>00184 
<a name="l00185"></a>00185   AT91C_BASE_SPI0-&gt;SPI_CSR[ channel ] &amp;= ~AT91C_SPI_CSAAT;
<a name="l00186"></a>00186 
<a name="l00187"></a>00187   <span class="keywordflow">return</span> 0;
<a name="l00188"></a>00188 }
<a name="l00189"></a>00189 <span class="comment"></span>
<a name="l00190"></a>00190 <span class="comment">/** @}</span>
<a name="l00191"></a>00191 <span class="comment">*/</span>
<a name="l00192"></a>00192 
<a name="l00193"></a>00193 <span class="keywordtype">int</span> Spi_Lock( <span class="keywordtype">void</span> )
<a name="l00194"></a>00194 {
<a name="l00195"></a>00195   <span class="keywordflow">return</span> xSemaphoreTake( Spi.semaphore, 1000 );
<a name="l00196"></a>00196 }
<a name="l00197"></a>00197 
<a name="l00198"></a>00198 <span class="keywordtype">void</span> Spi_Unlock( <span class="keywordtype">void</span> )
<a name="l00199"></a>00199 {
<a name="l00200"></a>00200   xSemaphoreGive( Spi.semaphore );
<a name="l00201"></a>00201 }
<a name="l00202"></a>00202 
<a name="l00203"></a>00203 <span class="keywordtype">int</span> Spi_Start( <span class="keywordtype">int</span> channel )
<a name="l00204"></a>00204 {
<a name="l00205"></a>00205   <span class="keywordtype">int</span> status;
<a name="l00206"></a>00206 
<a name="l00207"></a>00207   <span class="keywordflow">if</span> ( channel &lt; 0 || channel &gt; 3 )
<a name="l00208"></a>00208     <span class="keywordflow">return</span> <a class="code" href="group___error.html#g097f40c958abccd892d08f31b53c4dde" title="The requested index is not valid.">CONTROLLER_ERROR_ILLEGAL_INDEX</a>;
<a name="l00209"></a>00209 
<a name="l00210"></a>00210   <span class="comment">// Make sure the channel isn't already being used</span>
<a name="l00211"></a>00211   <span class="keywordtype">int</span> c = 1 &lt;&lt; channel;
<a name="l00212"></a>00212   <span class="keywordflow">if</span> ( c &amp; Spi.channels )
<a name="l00213"></a>00213     <span class="keywordflow">return</span> <a class="code" href="group___error.html#g5317aab1608afa7507da0214aec0dbab" title="Can&amp;#39;t get a lock on a resource.">CONTROLLER_ERROR_CANT_LOCK</a>;
<a name="l00214"></a>00214 
<a name="l00215"></a>00215   <span class="comment">// lock the correct select line </span>
<a name="l00216"></a>00216   <span class="keywordtype">int</span> io = Spi_GetChannelIo( channel );
<a name="l00217"></a>00217   <span class="comment">// Try to lock the pin</span>
<a name="l00218"></a>00218   status = Io_Start( io, <span class="keyword">true</span> );
<a name="l00219"></a>00219   <span class="keywordflow">if</span> ( status != <a class="code" href="group___error.html#gaa42bc036fbba18487ae9a15cd1f2f94" title="All&amp;#39;s well here.">CONTROLLER_OK</a> )
<a name="l00220"></a>00220     <span class="keywordflow">return</span> status;
<a name="l00221"></a>00221 
<a name="l00222"></a>00222   <span class="comment">// Disable the PIO for the IO Line</span>
<a name="l00223"></a>00223   Io_PioDisable( io );
<a name="l00224"></a>00224 
<a name="l00225"></a>00225   <span class="comment">// Select the correct peripheral for the IO line</span>
<a name="l00226"></a>00226   <span class="keywordtype">int</span> peripheralA = Spi_GetChannelPeripheralA( channel );
<a name="l00227"></a>00227   <span class="keywordflow">if</span> ( peripheralA )
<a name="l00228"></a>00228     Io_SetPeripheralA( io );
<a name="l00229"></a>00229   <span class="keywordflow">else</span>
<a name="l00230"></a>00230     Io_SetPeripheralB( io );
<a name="l00231"></a>00231 
<a name="l00232"></a>00232   <span class="keywordflow">if</span> ( Spi.users == 0 )
<a name="l00233"></a>00233   {
<a name="l00234"></a>00234     status = Spi_Init();
<a name="l00235"></a>00235     <span class="keywordflow">if</span> ( status != <a class="code" href="group___error.html#gaa42bc036fbba18487ae9a15cd1f2f94" title="All&amp;#39;s well here.">CONTROLLER_OK</a> )
<a name="l00236"></a>00236     {
<a name="l00237"></a>00237       <span class="comment">// Couldn't init for some reason, need to undo the IO lock</span>
<a name="l00238"></a>00238       Io_Stop( io );
<a name="l00239"></a>00239       <span class="comment">// now return with the reason for the failure</span>
<a name="l00240"></a>00240       <span class="keywordflow">return</span> status;
<a name="l00241"></a>00241     }
<a name="l00242"></a>00242     Spi.users++;
<a name="l00243"></a>00243   }
<a name="l00244"></a>00244 
<a name="l00245"></a>00245   <span class="comment">// Set the channel to locked</span>
<a name="l00246"></a>00246   Spi.channels |= c;
<a name="l00247"></a>00247 
<a name="l00248"></a>00248   <span class="keywordflow">return</span> <a class="code" href="group___error.html#gaa42bc036fbba18487ae9a15cd1f2f94" title="All&amp;#39;s well here.">CONTROLLER_OK</a>;
<a name="l00249"></a>00249 }
<a name="l00250"></a>00250 
<a name="l00251"></a>00251 <span class="keywordtype">int</span> Spi_Stop( <span class="keywordtype">int</span> channel )
<a name="l00252"></a>00252 {
<a name="l00253"></a>00253   <span class="keywordflow">if</span> ( channel &lt; 0 || channel &gt; 3 )
<a name="l00254"></a>00254     <span class="keywordflow">return</span> <a class="code" href="group___error.html#g097f40c958abccd892d08f31b53c4dde" title="The requested index is not valid.">CONTROLLER_ERROR_ILLEGAL_INDEX</a>;
<a name="l00255"></a>00255       
<a name="l00256"></a>00256   <span class="keywordflow">if</span> ( Spi.users &lt;= 0 )
<a name="l00257"></a>00257     <span class="keywordflow">return</span> <a class="code" href="group___error.html#gbe5b0c7c2a59668cdeb433375f091c2a" title="This resource has already been stopped too many times.">CONTROLLER_ERROR_TOO_MANY_STOPS</a>;
<a name="l00258"></a>00258 
<a name="l00259"></a>00259   <span class="keywordtype">int</span> c = 1 &lt;&lt; channel;
<a name="l00260"></a>00260   <span class="keywordflow">if</span> ( !( c &amp; Spi.channels ) )
<a name="l00261"></a>00261     <span class="keywordflow">return</span> <a class="code" href="group___error.html#g9ef65cc96e45d38307f661b86c330548" title="Lock attempt was unsuccessful.">CONTROLLER_ERROR_NOT_LOCKED</a>;
<a name="l00262"></a>00262 
<a name="l00263"></a>00263   <span class="comment">// release the IO</span>
<a name="l00264"></a>00264   <span class="keywordtype">int</span> io = Spi_GetChannelIo( channel );
<a name="l00265"></a>00265   <span class="comment">// release the pin</span>
<a name="l00266"></a>00266   Io_Stop( io );
<a name="l00267"></a>00267 
<a name="l00268"></a>00268   Spi.channels &amp;= ~c;
<a name="l00269"></a>00269 
<a name="l00270"></a>00270   <span class="keywordflow">if</span> ( --Spi.users == 0 )
<a name="l00271"></a>00271     Spi_Deinit();
<a name="l00272"></a>00272 
<a name="l00273"></a>00273   <span class="keywordflow">return</span> <a class="code" href="group___error.html#gaa42bc036fbba18487ae9a15cd1f2f94" title="All&amp;#39;s well here.">CONTROLLER_OK</a>;
<a name="l00274"></a>00274 }
<a name="l00275"></a>00275 
<a name="l00276"></a>00276 <span class="keywordtype">int</span> Spi_Init()
<a name="l00277"></a>00277 {
<a name="l00278"></a>00278     <span class="keywordtype">int</span> status;
<a name="l00279"></a>00279     status = Io_StartBits( IO_PA16_BIT | IO_PA17_BIT | IO_PA18_BIT, <span class="keyword">true</span> );
<a name="l00280"></a>00280     <span class="keywordflow">if</span> ( status != <a class="code" href="group___error.html#gaa42bc036fbba18487ae9a15cd1f2f94" title="All&amp;#39;s well here.">CONTROLLER_OK</a> )
<a name="l00281"></a>00281       <span class="keywordflow">return</span> status;
<a name="l00282"></a>00282   
<a name="l00283"></a>00283     <span class="comment">// Reset it</span>
<a name="l00284"></a>00284     AT91C_BASE_SPI0-&gt;SPI_CR = AT91C_SPI_SWRST;
<a name="l00285"></a>00285       
<a name="l00286"></a>00286       <span class="comment">// Must confirm the peripheral clock is running</span>
<a name="l00287"></a>00287     AT91C_BASE_PMC-&gt;PMC_PCER = 1 &lt;&lt; AT91C_ID_SPI0;
<a name="l00288"></a>00288   
<a name="l00289"></a>00289     <span class="comment">// DON'T USE FDIV FLAG - it makes the SPI unit fail!!</span>
<a name="l00290"></a>00290   
<a name="l00291"></a>00291     AT91C_BASE_SPI0-&gt;SPI_MR = 
<a name="l00292"></a>00292          AT91C_SPI_MSTR | <span class="comment">// Select the master</span>
<a name="l00293"></a>00293          AT91C_SPI_PS_VARIABLE |
<a name="l00294"></a>00294          AT91C_SPI_PCS | <span class="comment">// Variable Addressing - no address here</span>
<a name="l00295"></a>00295       <span class="comment">// AT91C_SPI_PCSDEC | // Select address decode</span>
<a name="l00296"></a>00296       <span class="comment">// AT91C_SPI_FDIV | // Select Master Clock / 32 - PS DON'T EVER SET THIS&gt;&gt;&gt;&gt;  SAM7 BUG</span>
<a name="l00297"></a>00297          AT91C_SPI_MODFDIS | <span class="comment">// Disable fault detect</span>
<a name="l00298"></a>00298       <span class="comment">// AT91C_SPI_LLB | // Enable loop back test</span>
<a name="l00299"></a>00299          ( ( 0x0 &lt;&lt; 24 ) &amp; AT91C_SPI_DLYBCS ) ;  <span class="comment">// Delay between chip selects</span>
<a name="l00300"></a>00300   
<a name="l00301"></a>00301     AT91C_BASE_SPI0-&gt;SPI_IDR = 0x3FF; <span class="comment">// All interupts are off</span>
<a name="l00302"></a>00302   
<a name="l00303"></a>00303     <span class="comment">// Set up the IO lines for the peripheral</span>
<a name="l00304"></a>00304   
<a name="l00305"></a>00305     <span class="comment">// Disable their peripherality</span>
<a name="l00306"></a>00306     AT91C_BASE_PIOA-&gt;PIO_PDR = 
<a name="l00307"></a>00307         AT91C_PA16_MISO0 | 
<a name="l00308"></a>00308         AT91C_PA17_MOSI0 | 
<a name="l00309"></a>00309         AT91C_PA18_SPCK0; 
<a name="l00310"></a>00310   
<a name="l00311"></a>00311     <span class="comment">// Kill the pull up on the Input</span>
<a name="l00312"></a>00312     AT91C_BASE_PIOA-&gt;PIO_PPUDR = AT91C_PA16_MISO0;
<a name="l00313"></a>00313   
<a name="l00314"></a>00314     <span class="comment">// Make sure the input isn't an output</span>
<a name="l00315"></a>00315     AT91C_BASE_PIOA-&gt;PIO_ODR = AT91C_PA16_MISO0;
<a name="l00316"></a>00316   
<a name="l00317"></a>00317     <span class="comment">// Select the correct Devices</span>
<a name="l00318"></a>00318     AT91C_BASE_PIOA-&gt;PIO_ASR = 
<a name="l00319"></a>00319         AT91C_PA16_MISO0 | 
<a name="l00320"></a>00320         AT91C_PA17_MOSI0 | 
<a name="l00321"></a>00321         AT91C_PA18_SPCK0; 
<a name="l00322"></a>00322   
<a name="l00323"></a>00323     <span class="comment">// Elsewhere need to do this for the select lines</span>
<a name="l00324"></a>00324     <span class="comment">// AT91C_BASE_PIOB-&gt;PIO_BSR = </span>
<a name="l00325"></a>00325     <span class="comment">//    AT91C_PB17_NPCS03; </span>
<a name="l00326"></a>00326   
<a name="l00327"></a>00327     <span class="comment">// Fire it up</span>
<a name="l00328"></a>00328     AT91C_BASE_SPI0-&gt;SPI_CR = AT91C_SPI_SPIEN;
<a name="l00329"></a>00329   
<a name="l00330"></a>00330     <span class="keywordflow">if</span> ( !Spi.semaphore )
<a name="l00331"></a>00331       vSemaphoreCreateBinary( Spi.semaphore );
<a name="l00332"></a>00332 
<a name="l00333"></a>00333     <span class="keywordflow">return</span> <a class="code" href="group___error.html#gaa42bc036fbba18487ae9a15cd1f2f94" title="All&amp;#39;s well here.">CONTROLLER_OK</a>;
<a name="l00334"></a>00334 }
<a name="l00335"></a>00335 
<a name="l00336"></a>00336 <span class="keywordtype">void</span> Spi_Deinit()
<a name="l00337"></a>00337 {
<a name="l00338"></a>00338   <span class="comment">// Shut down the SPI</span>
<a name="l00339"></a>00339   AT91C_BASE_SPI0-&gt;SPI_CR = AT91C_SPI_SPIDIS;
<a name="l00340"></a>00340  
<a name="l00341"></a>00341   <span class="comment">// Kill the semaphore</span>
<a name="l00342"></a>00342   <span class="comment">// vSemaphoreDestroyBinary( Spi.semaphore );</span>
<a name="l00343"></a>00343   <span class="comment">// Spi.semaphore = null;</span>
<a name="l00344"></a>00344   
<a name="l00345"></a>00345   Io_StopBits( IO_PA16_BIT | IO_PA17_BIT | IO_PA18_BIT );
<a name="l00346"></a>00346 }
<a name="l00347"></a>00347 
<a name="l00348"></a>00348 <span class="keywordtype">int</span> Spi_GetChannelIo( <span class="keywordtype">int</span> channel )
<a name="l00349"></a>00349 {
<a name="l00350"></a>00350   <span class="keywordtype">int</span> io;
<a name="l00351"></a>00351   <span class="keywordflow">switch</span> ( channel )
<a name="l00352"></a>00352   {
<a name="l00353"></a>00353     <span class="keywordflow">case</span> 0:
<a name="l00354"></a>00354       io = SPI_SEL0_IO;
<a name="l00355"></a>00355       <span class="keywordflow">break</span>;
<a name="l00356"></a>00356     <span class="keywordflow">case</span> 1:
<a name="l00357"></a>00357       io = SPI_SEL1_IO;
<a name="l00358"></a>00358       <span class="keywordflow">break</span>;
<a name="l00359"></a>00359     <span class="keywordflow">case</span> 2:
<a name="l00360"></a>00360       io = SPI_SEL2_IO;
<a name="l00361"></a>00361       <span class="keywordflow">break</span>;
<a name="l00362"></a>00362     <span class="keywordflow">case</span> 3:
<a name="l00363"></a>00363       io = SPI_SEL3_IO;
<a name="l00364"></a>00364       <span class="keywordflow">break</span>;
<a name="l00365"></a>00365     <span class="keywordflow">default</span>:
<a name="l00366"></a>00366       io = 0;
<a name="l00367"></a>00367       <span class="keywordflow">break</span>;
<a name="l00368"></a>00368   }
<a name="l00369"></a>00369   <span class="keywordflow">return</span> io;
<a name="l00370"></a>00370 }
<a name="l00371"></a>00371 
<a name="l00372"></a>00372 <span class="keywordtype">int</span> Spi_GetChannelPeripheralA( <span class="keywordtype">int</span> channel )
<a name="l00373"></a>00373 {  
<a name="l00374"></a>00374   <span class="keywordtype">int</span> peripheralA;
<a name="l00375"></a>00375   <span class="keywordflow">switch</span> ( channel )
<a name="l00376"></a>00376   {
<a name="l00377"></a>00377     <span class="keywordflow">case</span> 0:
<a name="l00378"></a>00378       peripheralA = SPI_SEL0_PERIPHERAL_A;
<a name="l00379"></a>00379       <span class="keywordflow">break</span>;
<a name="l00380"></a>00380     <span class="keywordflow">case</span> 1:
<a name="l00381"></a>00381       peripheralA = SPI_SEL1_PERIPHERAL_A;
<a name="l00382"></a>00382       <span class="keywordflow">break</span>;
<a name="l00383"></a>00383     <span class="keywordflow">case</span> 2:
<a name="l00384"></a>00384       peripheralA = SPI_SEL2_PERIPHERAL_A;
<a name="l00385"></a>00385       <span class="keywordflow">break</span>;
<a name="l00386"></a>00386     <span class="keywordflow">case</span> 3:
<a name="l00387"></a>00387       peripheralA = SPI_SEL3_PERIPHERAL_A;
<a name="l00388"></a>00388       <span class="keywordflow">break</span>;
<a name="l00389"></a>00389     <span class="keywordflow">default</span>:
<a name="l00390"></a>00390       peripheralA = -1;
<a name="l00391"></a>00391       <span class="keywordflow">break</span>;
<a name="l00392"></a>00392   }
<a name="l00393"></a>00393   <span class="keywordflow">return</span> peripheralA;
<a name="l00394"></a>00394 }
</pre></div><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Make Controller Kit</title>
<style type="text/css">
<!--
.footer {
	font-family: Verdana, Arial, Helvetica, sans-serif;
	font-size: 9pt;
	color: #999999;
}
-->
</style>
</head>

<body>
<hr size="1">
<div>
  <p class="footer">The Make Controller Kit is an open source project maintained by <a href="http://www.makingthings.com">MakingThings</a>.<br />
    MakingThings code is released under the <a href="http://www.apache.org/licenses/LICENSE-2.0.html" target="_blank">Apache 2.0 license</a>.<br />
    Bug tracker, development wiki and status can be found at <a href="http://dev.makingthings.com">http://dev.makingthings.com</a>.<br />
		This document was last updated on 5 Dec 2007.
</p>
</div>
<!-- Google Analytics Code -->
<script src="http://www.google-analytics.com/urchin.js" type="text/javascript">
</script>
<script type="text/javascript">
_uacct = "UA-769030-1";
urchinTracker();
</script>
</body>
</html>
